User guide

15
SmartBook for Renesas R8C/Tiny Microcontrollers
www.MightyMicons.com
These different operating modes are
managed by proper initialization in few
selected registers: CM0 (System Clock
Control Register 0), CM1 (System Clock
Control Register 1), HR0 (High Speed On-chip
Oscillator Control Register 0), OCD (Oscillation
Stop Detection Register).
From the reset condition, the micon gets into high speed
mode when the main clock is selected as the system clock
by configuring the Oscillation Stop Detection Register (OCD2=0).
In this mode, timers get high speed ring oscillator clocks, fRING-FAST, fRING or
fRING128. When the micon is activated for the medium speed mode, the CPU
gets the divided (by 2,4,8 or 16) main clock. Like the high speed mode, timers
also get similar clock options.
To get High/Low speed on-chip oscillator mode, on-chip ring oscillator should be
configured as the system clock (OCD2=1) and then either low speed or high speed
ring oscillator should be selected (HR01) and then the same is switched on
(CM14=0 for low speed oscillator, HR00=1 for high speed oscillator).
In addition, the CPU can get divided ring oscillator clocks, with the division of
1,2,4,8 or 16 by configuring the register CM1.
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From the reset
condition, the
micon gets into
high speed
mode when
the main clock is selected as the
system clock by configuring
the Oscillation Stop
Detection Register
(OCD2=0).